Auto-compensation for control voltage range of vco at low power supply

Abstract

Some aspects of the present disclosure relate to an apparatus, a PLL and an electronic device. The apparatus comprises a voltage-to-current (V2I) converter, a current controlled oscillator and a compensation current. The V2I converter is operable to receive a first voltage and generate a first current based on the first voltage. The current controlled oscillator is coupled to the V2I converter and operable to generate an oscillation signal based on a second current from or to the V2I converter. The compensation circuit is coupled to the V2I converter and operable to receive a third current from or to the V2I converter. The second and third currents vary in response to at least one of temperature variation and supply voltage variation of the apparatus. Variation direction of the third current is opposite to variation direction of the second current and different frequencies may be provided for a low supply voltage domain.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to and the benefit of Chinese Patent Application No. 201810610155.5 filed Jun. 13, 2018 which is hereby incorporated by reference in its entirety.BACKGROUNDField[0002]Embodiments of the present disclosure generally relate to voltage controlled oscillator (VCO), and more specifically, to auto compensation for control voltage range of VCO at low supple voltage.Related Art[0003]Portable or wearable electronic devices are popular nowadays. In these electronic devices, phase locked loop (PLL) is normally the clock generation source, and VCO is the key module for the PLL. For VCOs in portable or wearable electronic devices, high frequency is less desired. Instead, low power consumption is more desired for longer stand-by time or battery life.[0004]To pursue low power consumption, a low supply voltage, such as 1V, is often provided to VCOs. The VCOs provided with low supply voltage, however, encounter some issues...

AI Technical Summary

Benefits of technology

The present invention provides an apparatus that can compensate for changes in temperature and power supply to maintain a stable output. The apparatus includes a voltage-to-current converter, a current controlled oscillator, and a compensation circuit. The compensation circuit receives a current that changes in response to temperature and power supply variations, and its direction opposite to the direction of the current generated by the current controlled oscillator. This arrangement ensures that the output of the apparatus remains stable even when exposed to external factors.

Problems solved by technology

For VCOs in portable or wearable electronic devices, high frequency is less desired.

The VCOs provided with low supply voltage, however, encounter some issues, such as voltage headroom.

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